Stay-bolt structure.



l. R. FLANNERY & E. l. DODDS.

STAY BOLT STRUCTURE. APPLICATION FILED OCT. 25. 1911.

Patented June 11, 1918.

WTNESSES "nnrrnn snares "earner entice.

JOHN ROGERS FLANNERY AND ETI-IAN I. DO DLDS, FITTSBURGII, PENNSYLVANIA,ASSIGNORS TO FLANNERY BOLT COMPARE", O1? PITTSBURGH, PENNSYLVANIA.

STAY-BOLT STRUCTURE.

Specification of Letters Patent.

Patented June 11, 1918.

Application filed 0ctober25, 1917. Serial No. 198,479.

To all whom it may concern Be it known that We, JOHN R. FLANNERY andE'lI-IAN I. Doors, citizens of the United States, and residents ofPittsburgh, in the county of Allegheny and State of Pennsylvania, haveinvented certain new and usefullmprovements in Stay-Bolt Structures; andwe do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to improvements in staybolt structures and moreparticularly to means for denoting the condition of integrity ofstaybolts for boilers,the object of the invention being to providesimple and efficient means whereby the condition of the bolt may beascertained without removing the same or any part thereof from theboiler and to so construct and arrange such means that the desiredinformation may be obtained by audible signal means Within the staybolt.

With this object in view the invention consists in certain novelfeatures of construction and combinations of parts as hereinafter setforth and pointed out in the claims.

In the accompanying drawings, Figure l is a View illustrating anembodiment of our invention. Fig. 2 is a sectional'view on the line 22of Fig. 1, and Fig. 3 is a view showing a slight modification.

1 represents a staybolt for boilers having a tell-tale bore 2 and thelatter may be made slightly conical at the inner end of the bolt, asindicated at 3.

Located within the inner end of the bore 2 is a tube l having a hole 5at its inner end. The other end of said tube may be somewhat enlargedand made conical at (3 to fit the conical end portion of the bore 2.

' The tube 4 is preferably made of non-magnetic material and contains abar or piece of iron 7 which is normally embedded in a body of solublematerial 8 (such as salt) and is normally held immovably thereby. Theopen end of the tube 4 is closed by a plug 9 (which may be made of arefractory element similar to clay) and the iron piece 7 is so disposedin the body of soluble mabore, and an iron piece terial 8 that it willbe normally out of contact with said plug as well as with all parts ofthe interior surface of the tube.

. If the pole of an electro-magnet 10 having its coil included incircuit with a source of alternating current supply, indicateddiagrammatically at 11, be placed in proximity to the end of thestaybolt, the iron piece 7 would tend to be attracted by it but undernormal conditions said iron piece will be held immovable by the solublematerial 8 in which it is embedded. Should the bolt become ruptured andthus permit the entrance of moisture into the telltale bore 2, suchmoisture would enter the tube l through the hole 5 and dissolve thematerial 8, thus releasing the iron piece 7. Under such conditions theplacing of the magnet in proximity to the end of the bolt will cause theiron piece to rattle within the tube and thus afford an audible signal.denoting the ruptured condition of the bolt.

Instead of forming the tube 4 with the plug portion 6 and providing aseparate plug in the latter, We may provide a tube 12 cylindrical fromend to end and a separate plug 13 which serves to close the bore 2 andalso the end of said cylindrical tube, as shown in Fig. 3.

Having fully described our invention What we claim and desire to secureby Letters-Patent, is: y

l. The combination with a staybolt having a tell-tale bore, of solublematerial in said normally held fixed by said soluble material andadapted when said material shall have been dissolved by the entrance ofmoisture into the tell-tale hole, to be moved by the application ofanelectro-magnet having its coil included in an alternating currentsource of electrical supply to provide an audible signal denoting aruptured condition of the bolt.

2. The combination with a staybolt having a tell-tale bore, of anon-magnetic tube located within said bore and having an entranceopening for moisture, soluble material in said tube, an iron piecenormally embedded in said soluble material, and a closure for said tube.

3. The combination with a staybolt having a tell-tale bore,

of a tube therein having a hole at one end, and a plug portion atspecification in the presence of two subscribthe other end located inthe entrance of said mg Wl DHGSSGS.

tell-tale bore a 311w olosin the end of the tube, so1uble n1a teri alinclo sed Within said L 5 tube, and an iron piece normally embedded insaid soluble material and out of engage- Witnesses: ment with the Wallsof the tube. F. H. ALLISON, In testimony whereof We have signed thisEDWIN S. RYGE.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, I). 0.

